Cord-circuit repeater



s; P. sHAcKLEToN 5T AL v com) CIRCUIT REPEATBB Filed oct. v, 1925 shuts-Sheet 2 I N V EN TORS MMM/m15 www BY W ATTORNEY Fatented July 12, 1927.

vneural) STATES PATENT OFFICE.

SAMUEL P. SHACKLETON, 0F WYOMING, NEW JERSEY, AND`LEE L. GLEZEN, 0F NEIN BRIGHTON, NEW YORK, ASSIGNOR-S TO AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK. v

CORD-CIRCUIT REPEATER.

Application filed October 7, 1925. Serial No. 61,096.

This invention relates to transmission lines and more particularly to improvements in arrangements for interconnecting such lines through repeater apparatus.

Heretofore it has been the practice to set aside certain specified positions in a switchboard to handle calls requiring telephone repeaters. When a regular operator received a call between two lines which needed to be coupled by a repeater connection she would then transfer the call completely to an operator at one of the special repeater positions. The special repeater operator would then build up the remaining circuits, establish the connection through a repeater cord circuit, monitor on the connection and have general supervision of the call until its absolute completion. This practice placed quite a heavy traffici load on the special repeater operators.y The time required for the repeater operator to complete the many duties required by each call made it necessary to provide a large number of special repeater positions and operators and to have each repeater operator handle comparatively few repeaters. The service, however, was subject to considerable delay. This practice caused some uncertainty in securing repeaters on designated connections since the call, which was passed by the originating operator was received by a regular operator who then transferred the call and a new operator to the connection had to receive the instructions. On a certain, proportion of the calls the originating operator failed to repeat the call for a repeater the second time and the connection would be completed without a repeater. This resulted in eXtra traffic load on the originating` operator as well as on the operators atthe repeater point.

YWith the arrangements of this invention the regular operator upon receiving a call between two lines which need t0 be coupled by a repeater connection does not effect a complete transfer of the call to the repeater operator but merely communicates with her over a call circuit and tells her to interconnect by a repeater cord circuit these two lines, special jacks for which are located at the repeater operators position. Means are provided by this invention whereby the regular operator will then complete the connection and have complete supervision thereover until its absolute completion. In other words with the arrangements of the invention all that the special repeater operator has to do is to connect a repeater cord circuit. operatively between the two designated lines and all of the other duties fall on the regular operator. Under such conditions the special repeater operator is able to handle a great many more repeater cord circuits than heretofore and connections of this type'may be completed in a much shorter time. Furthermore7 the number of special repeater positions may be greatly reduced. Accordingly, it will be seen that the arrangements of the invention serve to materially increase the speed of the service, while at the same time reduce the equipment and personnel required. Further features and Objects of the invention will ,appear more fully from the detailed description thereof hereinafter given.

The invention may be more fully understood from the following description together with the accompanying drawing in the Figures l and 2 of which the invention is illustrated. Figs. l and 2 when taken together show a circuit diagram of a preferred form of the invention. y

In the upper portion of Fig. lare shown two lines L1 and L2 terminating in the multiple jacks J1, Jl, J2 and J2 respectively located at positions Ona switchboard takencare of by a'regular operator. The operators cordcircult 29 1s shown schematically.

Associated with the line Ll and the circuit 3l is a relay 37'. Thisl relay serves to connect line L1 to a circuit 35 and to connect circuit 31 to a circuit 33. Circuits 33 and 35 lead to the twin jacks J 3 and J 3 which are located at another position on the switchboard known as a special repeater operators position. Another set of twin jacks J 4 and J 4 are located at this special repeater operators position and may be connected to the line L2 and circuit 32 by means of the relay 38 and circuits 34 and 36. In Fig. 2 is shown in detail the repeater cord circuit for interconnecting lines Ll and L2 through the twin jacks I, J3 and JMJJ. Associated with the twin jacks are the balancing networks N, and N2 adapted to balance the lines L1 and L., respectively. The cord cir; cuit repeater includes a two-way two element repeater comprising the repeater elements R, and R2 and the usual hybrid coils 26 and 27. A gain control device including the sliding switch 28 is also provided 'for setting the gain et the repeater elements. @ther details ot the arrane'einents will appear more iully trein the Yfollowing detailed description ot the operation of the invention.

For purposes ot illustration let it be assuined that the regular toll operator at a position on the outward board has built up a connection between 'two'lines` such as Ll andv L2 rl`he regular toll operator-will be connected to these lines by her cord circuit 29', the plugs P1 and P,r of which beinginserted respectively in the multiple jacks J1, Jl andV 55.12. It the* regular toll operator now desires to have these two lines intercon-` nected throughfrepeater apparatus she will communicate over a call circuit (not shown) with the special repeater' operator at a. difterent position 'on the switchboard'7 such as the position atV which the cord ,ircuit repeater ot 2 would be located. rThe special repeater operator would then be instructed to vinterconriect the two lines L. and L2 by a repeater cord circuit. As has been'pointed out heretofore twin jacks, such as J3, J3 and JUL', tor these lines would be provided at the special repeater operators position. The repeater operator would then insert-the twin plugs 131 P2 and P4 P4 ot a repeater co d circuit into these twin jacks. The repeater operatorwill then advance the sliding switch 2S ot her gain control apparatus troni the Zero position to one of the other positions. Q nly the switching or lrey ineclrinisni ol the gain control apparatus has been shown. The gain control apparatus would consist ot potentioineters and apparatus tor adjusting them' associated with the input circuits ot the repeater eleinents to vary the gain thereof. The separate circuits shown connected to the positions of the sliding` isin tor in' conswitch 28 would control the nlech operating the potentioinet rs. fis

trol mechanism for repeaters is well lrnown in the art no further description thereof will-be given. lt is pointed out that thel operation" of the gain control inechanisin may be either inanual or automatic. s'has been pointed out, the repeater operator will advance the switch 28 oit her gaincont-rol apparatus as soon as she plugs in her repeater cord circuit. This will 'put ground on the tollowinej simplex circuit; trein ground conductors 40 and il, winding oir-relay i. windings ot retard coil 6, tip and conductors o" plug P l. circuit 36. windings ol retard coil 42, circuit 43. windings oit relay 38 to battery and ground. The closing ot this circuit will operate relay 38. The operation ot relay 38 will disconnect line L2 troni circuit 32 leading to the operator cord circuit and will connect line L.. to the conductors 36 d thence over the tip and ring conductors el plug l?, and the contacts ot re'- 2Ol conductors lill, and thence over conductors 45 and 46 and through the monitoring coils i7 and Yl-S. ln other words the operation" ot relay 3S will connect line L2' to thev talking windings Ot the repeater and will'connect the regular operatorscord circuit 29 to' the monitoring"windingsv ot the repeater. The operationol the Asliding switch Q8 of the rel i peater gain control apparatus will also close thetollowing Sineplex circuit: from ground, contacts of switch 28, conductors'i@ and '41, windings ot relay Sand retard coil 5,'tip and ring conductors ot pluglPs, conductors 35, windings ot retard coil 452,', conductors 43, and vthence through the windings of re` lay 37 to battery andgrounc'l,thus operating relay 37. The relay p'erforinssinii# lar functions to those ofrelay 88. Accord ingly the relay 37' upon operating will ccnnect lineLl tothe input windings' ot repeater its and will'connecttlie operators cord`29 te the monitoring windings of the repeater.

The special repeater'operator will beprovided with monitoring apparatus which has not been shown in vthel drawing. When she operates theV sliding switch 28 of her gain control apparatu's'ishe will listen inon the connection by 'her monitoring apparat-us to deterinine whether she has been able to in" troduce `any gain in the connection by the repeater apparatusf This ymay 'be' deter-Y mined by the presence or absencev ot'aconditionvot singing on the line. ltsh'e'iinds that it was noti possible to vintroduce any gain by the repeaters she will restore her keyQS to the Zerov position. This will allow lines L., and L, to be interconnected through thetoll operators oordcircuit 29 and the repeater cord will be I-reinovedV troni the lines. 'However it it is found that the reA peater cord circuit does serve to introduce a desired gain inthe circuit', the switch 28; will be lett in its actuated'position andY the inonitoringl and other supervision" will be' done by the regular toll operator whose set has been connected to the monitoring windings 4T' and i8 as has been pointed out here'- toifore. Y

lt hasbeen pointed out that when the switch 28 is operated that certain circuits` are closed through lthe windings oi' relays 3 and l and that these relays are operated' thereby. The voperation otrelays 3 and #i will cause certain circuit conditions to be set up lin the repeater cord ciricuit, 'ainon'g which are the ol'lowing;ground will be lou Ill)

ill

applied from switch 28 over conductors 40 and. 41, armature and contact of relay 4, conductor 49, armature and contact ofrelay 3, contact and armature of relay 12, conductor l, armature and contact of relay 13, conductor 52, winding ot relay 14, to battery and ground, thereby operating relay 14. The operation ot relay 14 Will pull open its right hand larnniture and contact and prevent the ground which uias also applied to conductor from being applied at this time to-conductor and thence to the ringing relays 15 and 16. he operation of relay 14 will close at its left hand contact a circuit l'roni conductor 5() towhich ground has been applied, over conductor 53, contact and armature of relay 14, contact and armature ot' relay 21, conductor 54, 'winding oit' marginal relay 23.,- to battery and ground. The closing of this circuit will operate rela;7 which will open the short circuits 55 and 56 Vacross the input circuits oi the repeaters l, and Rl and hence place them in condition 'for operation.

Under the above described conditions a re-ring signal would operate in the following manner. For example, signaling current applied by the distant operator at the other end of line L1 Would come in over line Ll and would operate the signal current responsive relay 12. This would open at its contact and armature the previously traced circuit through relayv 14 and'would deenergize relay 14. This wouldY allow ar circuit to be closed over the rle'hthand armature aud Contact or-clay 14 as Vfollows from ground'appiied to conductor 50, arma-v ture and contact ot relay 14, conductor 60, winding of relay 15, to batteryv and ground, thereby operating relay 15. This Would connect a source oi suitable 'signaling current, such as 2O cycles, to the sleeveconductors of plugs l), and P3 and thence over vconductors 33 and 31 to the signal responsive apparatus in the regular operators cord circuit 29. In an operators cord circuit,y

such as 29, the direction of the incoming re-ring` signal is unimportant. ln a similar' manner a re-ring signal coming in overV line L, would operate the relay 13 and causeY the deenergization of relay 14 and the oper'ation of relay 16 which would apply signaling` current to the sleeve conductors'oit-plugs P, and P4 and thence over conductors 84 and 32 to the operators cord circuit 29. The release or relay 14 in the case ot' a rering signal would also release relay 23 and close the short circuits across the inputs of the repeaters and thus prevent any singing7 at this time.

lt the regular toll operator desires to ringV out over either of the lines L, or L2 While these lines are interconnected by the 'repeater cord circuit the'operation is as follows: It, for example, the operator desires operate relay 17 Which Will close the following ci1cuit,-from ground, armature andv contact of relay 17, conductor 61, winding ot relay 19, to battery and ground. This Will operate relay 19 which i 7ill connect conductors 10 and 11 to the tip and ring conductors of plug P3. Accordingly the sie'- naling current applied Vfrom the operators` cord circuit 29 will be transmitted from conductors 10 and 11, over the tip and ring conductors of plug P3, over conductor 85, and thence out over the line L1. The operation or relay 17 Will also-apply ground 'to conductor 63 and thus operate relay 21. This Will open the short circuit around resistance 22 and include this resistance in the circuit t marginal relay 23 causing it to release. This will close short circuits 55 andv 56 across the input circuits of the repeaters and thus prevent any singing from tal;- ing place at this time. In a similar manner ringing current transmitted from the operators Lcord 29 to conductors 32 and 34 would be applied to conductors Sand 9 and Would operate relay 18. This :in turn would operate relay `2O and connect conductors S and 9 to the tip and ring conductors of plug Pet from which the ringing current would be applied' to conductors 3 6 and thence out over line L5. The short circuits across the repeater input circuits 'would' also be closed i at thisv time.

Vhen the original operator receives a disconnect signal from the line she removes her cord circuit`29 from the multiple jacks such asJl, Jil. This Would cause the relay 64 to release. This relay would vhave been energized When the original operator connected with Vthe line. The release of relay 64 Will allow the following simplex circuit to 'be completecL-from yground and battery, contactof relay 64, conductor 65, to the midpoint of resistance 67 and then over the parallel simplex circuit comprising conductors 83, sleeve conductors of plugs l)3 and PP, conductors 10 and 11. conductors 44,

conductors 45 and 46, windings of monitoring coils 47 and 48, to the midpoint of these coils, and thence over conductor 24 and through lamp 25 to ground. The completion of this simplex circuit will operate lamp 25 Which will notify the special repeater operator `to remove the 'repeater cord circuit from the line.

A 'further advantage of the arrangements ot the invention consists in improved conditions of'balance during a repeater connection. vThis is due tothe fact that when the repeater cord circuit of this invention is lli? l ifi connected to the line all of the multiple cable and associated apparatus at the switchboard is disconnected therefrom, In other words the repeater cord circuit is connected directly to theline section alone, over the contacts of relay 37, and circuit 5l and the multiple cable apparatus is eliminated from the talking connection. rllliis multiple cable apparatus will vary tosuch a degree due to moisture and weather conditions, that it would aii'ect the balance of' the line. Vif ith the arrangements of the invention however all this Variation is eliminated as the artificial line only has to balance the line section Ll itself.

ldlhile the invention has been disclosed iii certain specific arrangements which are deemed desirable, it is understood that it is capable of embodiment in many other arrangements without departing from the spirit of the invention as defined by the apended claims.

That is claimed is:

l. A transmission line normally7 terminating in jacks located at a switchboard position, circuit arrangements associated with said line and terminating in jacks located at a different switchboard position, relay means associated with said line and said circuit arrangements, a cord circuit adapted to be associated with saidjacls at mentioned switchboard position, and means in said cord circuit for operating` saidrelay means whereby said line will bedisconnecti ed from said first mentioned jacksrand con;

iiectedv to the talking conductors ofsaid second mentioned jacks and said first inentioned iaclis will be connected tothe sleeve conductors of saidsecond mentioned jacks.

2. A pair of'transmission lines normally terminating at aV regular switchboard position, a cord circuit at said position for interconnecting saidjlines, auxiliary circuits associated with said lines and terminating at a second switchboard position, a cord circuit at said second switchboard position for interconnecting' said auxiliary circuits, supervisory apparatus in said second coidcircuit,

and relay means associated with said lines and said auxiliary circuits 'for disconnecting said lines from said first cord circuit and for connecting' said lines to certain of4 said auxiliary circuits for interconnection through said second cord circuit and for connecting said first cord circuit to certain olv said auxiliary circuits for connection with said supervisory apparatus in said second cord circuit.

3. A transmission line normally terminating at a regular switchboard position, a cordy circuit connected to said line` at said position, a pair of auxiliary circuits associatedwvith saidiline and terminating at a second switchboard position, a cord circuit at said second position havinga talking circuit and alsupersaidl second visory circuit, means for connecting the talking circuit of saidsecond cord circuit with the first auxiliary circuit, means for connecting the supervisory circuit of said second cord circuit with the second aux iary circuit, and relay means associated with said line and said auxiliary circuits and controlled by said second cord circuit for disconnecting said line`V from said iirst cord circuit and connecting said line to, said first auxiliary circuit and for connecting said first cord circuit to said second auxiliary circuit.

4. A transmission line normally terminati1 iga`t a regular, switchboardA position, aV cordl circuit connected to said liney at said position, a pair of auxiliaryy circuits associated with said line and terminating at a second s witcllboard position, a cord circuit at said second` position having a talking circuit and a supervisory circuit, means for connectingthe talking circuit of said second cord circuit with the first auxiliary circuit, means for connecting the supervisory circuit.. of said Asecond cord circuit with the second. auxiliary circuit, relay means associated with said line and said auxiliary circuits and controlled by said second cord circuit 'for disconnecting said line from said first cord circuit and, connecting said line t0 saidrst auxiliary circuit aiidfor connecting said first cordcircuit to said secondv auxiliary circuit, a signaling circuit in said second cord circuit, signal responsive means associatedwith the talking circuitof said second coi-1d circuit for controlling said signaling circuit, and means controlled by said signaling circuit for applying signaling current to said secondl auxiliary circuit.

5. A transmission line normally terminating. at a regular switchboard position, circuit connected to said line at said a cord Y position, a pair of auxiliary circuits associated with said line'and terminating at a secondlswitchboard position, a cord circuit at saidfsecond position having a talking circuit and a supervisory circuit, means for connecting the talking' circuit of said second` cord circuit with the first auxiliary circuit, means for -connecting the' supervisory circuit of said second. Vcord circuit with the second auxiliary circuit, relayV means associated with said line andsaid auxiliary circuits and controlled by said disconnecting said line from said first cord circuit andyconnecting said line to said first auxiliary circuity and for connecting said' fiivst'cord circuit to said secoiul` auxiliary circuit, signal; responsive means associated witlisaidsupervisory circuit in `said second cord circuit, and means controlled thereby for connecting said supervisory circuit to said talking circuit in said second cord circuit.

6. A transmission line normally terminating at a regular switchboard position, a cord second cord circuit for circuit connected to said line at said position, a. pairof auxiliary circuits associated with said line and terminating at a second switchboard position, a cord circuit at said second position having a talking circuit and a supervisory circuit, means for connecting the talking` circuit of said second cord circuit with the first auxiliary circuit, means for connecting the supervisory circuit ol said second cord circuit With the second4 auxiliary circuit, relay means associated with said line and said auxiliary circuits and controlled by said second cord circuit for disconnecting said line from said first cord circuit and connecting said line to said first auxiliary circuit and for connecting said first cord circuit to said second auxiliary circuit a simplex circuit associated With said second auxiliary circuit and the supervisory circuit in second cord circuit, signaling means in said secondcord circuity controlled by said simplex circuit, and means cont-rolled by said lirst cord circuit for control-ling` said simplex circuit.

In testimony whereof, We have signed our names to this specification this 5th day of October, 1925.

SAMUEL P. SHAGKLETON. LEE L. GLEZEN. 

